The present invention relates to methods for monitoring a fluid in or near real-time and, more specifically, to methods for monitoring a fluid for the purpose of identifying microbiological content and/or microorganisms therein and determining the effectiveness of a microbiological treatment.
The presence of bacteria and other microorganisms in a substance is often determined after enhancing low levels of biological material to detectable levels. In some cases, a sample of the substance can be cultured under conditions that are conducive for growth of a particular biological material. In other cases, nucleic acid amplification techniques, such as polymerase chain reaction (PCR), can be used to increase levels of nucleic acids. Culturing methods, in particular, may sometimes be non-specific, as many different types of microorganisms may grow under the chosen culturing conditions, whereas only certain microorganisms may be of interest for an analysis. Furthermore, both culturing and nucleic acid amplification techniques are often constrained by the timeframe over which they are conducted. PCR techniques, for example, may take several hours or more to produce sufficient nucleic acid quantities for analysis, and culturing may take days to weeks to complete. Methods for real-time or near real-time monitoring of bacteria and other microorganisms are believed to not yet have been developed.
The present inability to monitor bacteria and other microorganisms in a sufficiently rapid manner can have significant ramifications for a variety of commercial and industrial products and processes. For example, due to a limited shelf life, a product (e.g., a foodstuff or pharmaceutical) may have been transported to a store and released for public consumption before product quality testing has been fully completed. By the time a biological contamination has been uncovered, it can oftentimes be too late, as consumers may have already been exposed to the contaminated product. Not only can human health be compromised, but valuable process time, raw materials, and other resources may have been lost by preparing and distributing a contaminated product.
Although biological contamination is a recognizable concern in the food and drug industry, the problem of contamination by bacteria and other microorganisms extends to a much broader array of fields, including those not directly impacting human health. For example, and without limitation, biological monitoring of water treatment and wastewater processing streams, including those from refineries, can be of significant interest due to downstream contamination issues. In subterranean oil and gas operations, biological contamination can reduce production and/or result in biofouling of equipment and wellbore surfaces. In addition, biological contamination on some solid surfaces can lead to structural defects, including corrosion, that ultimately may result in mechanical failure. In short, any industry in which monitoring of biological contamination or concentration is of interest could potentially benefit from more rapid detection techniques for biological materials.
While monitoring for the presence of biological materials, there is often also an interest in reducing or otherwise preventing biological contamination within a substance, such as a fluid. In some instances, a biocide may be used to slow or stop biological growth. Although biocides may often be effective for addressing the particular biological contamination, their effects can sometimes be slow acting. In addition, at least some members of a population of microorganisms are able to survive various biocide treatments.